As in all pressure fluid mechanisms of this type, the cylinder block is mounted to rotate relative to the cam and the internal fluid distributor valve must be constrained with respect to said cam with respect to said relative rotation to rotate with said cam.
When the pressure fluid mechanism is coupled to a brake including a stack of disks contained in a special chamber, the invention takes advantage of the special structure of the braking device for simplifying the connection between the internal fluid distributor valve and the cam.